The “whole of NEM” tab has been provided to provide an overview of how each client’s region of focus interacts with the other regions in the NEM. The following is a snapshot taken on the afternoon of Friday 29th May 2015, in the 14:15 dispatch interval:
This screen is comprised of 3 parts – each of which is described below:
On the left-hand side of the display is a geographical view of the current (5‑minute) dispatch data across the NEM – with arrows showing direction of flow and (in this instance) “Heywood”, from VIC to SA, is shown as red because the interconnector is constrained.
At the top of the map you will see two clocks:
- On the left ‘Clock Time’ displays the time on your PC clock.
- On the right ‘Current Dispatch Time’ displays the current dispatch interaval.
The dispatch interval is identified by the minute that the 5-minute period ends on – for example in the screenshot above, the current time is 09:12 so we are in the 09:15 Dispatch Interval.
For each region of the NEM, you will see a box that displays summary data for the given dispatch interval. From top-to-bottom, this shows 5-min interval data for:
- Regional Price
- Regional Total Demand
- Cumulative Price
All 3 of these data elements are coloured on a sliding scale between blue (low) and red (high).
Each interconnector for the NM is represented by a graphic like shown above.
The pipe graphic on the left shows:
- The arrows on the pipe represent the direction of the flow over the interconnector
- The pipe will turn red when the interconnector is flowing a a limit (this is when price separation can occur).
The box on the right shows:
- The red number is the flow limit (normally) in one direction, indicated by number sign.
- The blue number which is the magnitude of the flow.
- The green number which is the flow limit, for this dispatch interval, in the other direction.
You can think of the number sign on the interconnector flow as being ‘Hobart-centric’, i.e. Flow north or west (away from Hobart) is positive, and flow south or east (towards Hobart) is negative.
Estimated Trading Prices Table
In the middle section is a table showing 5-minute trading prices for each region:
- The top box is the actual trading price for the immediately preceding 5-minute interval;
- The middle box is actual trading price for the current 5-minute interval (this is a key number you will want to keep a close eye on); and
- The bottom box is the estimated trading price for the next 5-minute interval.
Please keep in mind that the NEM operates in AEST year-round – i.e. no daylight savings.
The Trading Price is the key measure for most deSide users, as it’s the price that dictates what is paid (for consumption exposed to spot prices). Prior to 1st October, 2021, the trading price was calculated every 30-mins (a.k.a. a 30-minute trading interval) that was the time-weighted average of the contained 6 x 5-minute dispatch prices. Since 1st October, 2021 a significant rule change has been implemented that trading prices are no longer a time-weighted average, and will equate to the 5-minute dispatch price.
Predispatch Forecast Chart
On the right-hand side are 5 charts (one per region) showing the past 24 hours and then AEMO’s predispatch forecasts out till 4am the day after tomorrow. The chart shows:
- Regional demand;
- Regional available generation.
This is illustrated as follows:
Each of these charts is for a singular region of the NEM and each has a different colour scheme. Below we will explain the chart in the screenshot above (for the NSW region) so that you can understand the different elements of the chart. The same principles can be applied to the other regions but keep in mind that the colours will be different.
- The dark blue shaded area at the back applies to the right x-axis and is the Available Generation Capacity (i.e. aggregate of all bids in that region of the NEM for that time period). Beyond the current point in time (the white slice in the chart), this is the predispatch forecast for Available Generation Capacity.
- The light blue shaded area at the front applies to the right x-axis and is the Scheduled Demand (i.e. demand that AEMO dispatched for). Beyond the current point in time (the white slice in the chart), this is the predispatch forecast for Scheduled Demand.
- The orange line applies to the left x-axis and is the actual 5-min trading price for the past day.
- The vertical ‘slice’ near the middle of the chart represents the current point in time.
- The yellow line applies to the left x-axis and is the P30 forecasted trading price trended until 04:00AM next day.
- There are light grey lines behind the yellow line (which are sometimes more difficult to see on the chart). These are the main P30 predispatch price sensitivities for the given region, these are generally:
- Region Demand + 100MW
- Region Demand + 200MW
- Region Demand – 100MW
- Region Demand – 200MW
The Display element within deSide has been developed in order to provide clients a clear view of what’s currently happening with respect to the electricity market, and likely to happen in the immediate future (and hence by which they can make decisions in terms of whether to curtail consumption, or switch on back-up generators, etc…).